Small piece folder



July 12, 1966 E. F. KAMBERG ETAL 3,260,518

SMALL P IECE FOLDER 5 Sheets-Sheet 1 Filed Jan. 21, 1965 INVENTOR. M6-Jay y 12, 1966 E. F. KAMBERG ETAL 3,260,513

SMALL P IEGE FOLDER 5 Sheets-Sheet 2 Filed Jan. 21, 1965 INV NTOR.

y 1966 E. F. KAMBERG ETAL 3,260,513

SMALL PIECE FOLDER 5 Sheets-Sheet 5 Filed Jan. 21, 1965 y 2, 1966 E. F. KAMBERG ETAL 3,260,518

SMALL PIECE FOLDER 5 Sheets-Sheet 4 Filed Jan 21, 1965 United States Patent Oflice 3,250,518 Patented July 12, 1966 3,260,518 SMALL PIECE FOLDER Eduard F. Kamberg, Des Plaines, and Haroid G. Roberts, Medinah, Ill., assignors to Chicago Dryer Company, Chicago, 111., a corporation of Illinois Filed Jan. 21, 1965, Ser. No. 434,335 16 Claims. (Cl. 270-62) This invention relates to apparatus for folding small items of fiatwork, such as towels, pillow cases, napkins and the like, and more particularly, pertains to a novel apparatus for automatically quarter-folding such small items along intersecting axes without any need for employing complex measuring or gauging devices. This application is a continuation-in-part of our copending application Serial No. 355,375, filed March 27, 1964, and now abandoned.

In folding machines of the type hereinafter described in detail, a regulating or measuring means must normally be employed to assure folding along proper, centrally disposed axes of the foldable article. Obviously, unless an item to be quarter-folded is folded precisely at the desired midpoint of the transverse and longitudinal axes thereof, the appearance of the resulting article is unattractive and, in addition, presents stacking problems because of its nonuniform thickness.

Such regulating -or measuring means may comprise various sensitive electrical devices which not only possess a large initial purchase price, but also are expensive to maintain and the greatest source of mechanical difliculties in machines of this type. As an alternative to the use of costly, complex, automatic measuring devices, operatorcontrolled regulating devices may be employed for governing the folding mechanisms.

Although less complex in design and less costly, such controlled devices necessitate a new setting by the operator with each change in size of the articles being folded. Therefore, unless the articles being folded are of the same dimensions, the operator must adjust the folding elements to conform with each change in size of the articles. Such setting requirement necessitates either a preliminary sorting of all the foldable items into groups of uniform size to minimize adjusting, or in the alternative, requires a new setting for substantially each article folded. With either procedure large amounts of time are wasted.

In accordance with this invention, folding apparatus utilizing no complex or expensive components and specifically designed for small pieces, such as towels and pillow cases, is provided. The small piece folder hereinafter described, although utilizing no complex measuring or operator-controlled components, readily and precisely folds a small foldable item into quarters along intersecting axes disposed at right angles to each other. The apparatus is compact in size, automatic and rapid in operation, and actuated into the various folding procedures by contact of a moving foldable article with actuators for switches which control means motivating the folding elements.

The provided folder also employs novel stacking elements which assure desired vertical alignment of the folded articles regardless of the material of composition of the articles and their specific size, as will hereinafter be explained in greater detail.

It is an object of this invention, therefore, to provide a novel automatic, small piece folder apparatus which utilizes no complex measuring components, but relies on passage of a foldable article through the apparatus for actuation of the folding elements.

It is another object of this invention to provide a small piece f-olding apparatus in which the working elements are exposed and readily accessible whereby jamming of a foldable article in the device may be prevented by the operator in complete safety.

It is yet another object of this invention to provide a small piece automatic folding apparatus, composed of a minimum number of components of low cost, which is both durable and efiicient in operation.

It is another object of this invention to provide folding apparatus utilizing automatic stacking and conveying means which automatically stack and convey the small piece items discharged by the apparatus to a desired location for disposal.

It is yet another object of this invention to provide a folding apparatus employing stacking apparatus which assures desired vertical alignment of the folded articles into stacks of desired size.

The above and other objects of this invention will become more apparent upon reading the following detailed description in the light of the accompanying drawings and appended claims.

In one embodiment of this invention a small piece fold.- ing apparatus is provided which employs a substantially horizontal conveyor which may be formed of a plurality of continuously moving tapes or belts driven by rotating roller members. The folding apparatus is designed to accommodate the output of any ironer and, accordingly, the speed of the provided folder may be regulated so that it may keep pace with the output of ironers, such as are employed in laundries. The moving foldable article while carried by the continuous tape members is brought into contact with an assemblage of folding elements, such as is disclosed in Kamberg Patent No. 3,094,321, which issued June 18, 1963.

The assemblage enables the leading edge of the foldable small piece to ride up retractable fingers onto an anvil-like plate into engagement with a vertical switch actuator. Movement of the latter element actuates means for urging a clamp bar against the anvil surface with the leading edge portion of the foldable article therebetween. Simultaneously, means for retracting the inclined fingers are actuated, thereby enabling the remaining portion of the towel or the like to be carried beneath the overlying anvil surface. Upon disengagement of the trailing terminal end of the foldable piece from a switch actuator positioned in advance of the anvil surface, means are actuated enabling the clamp bar to be retracted and allowing the released once-leading edge of the foldable article to drop over the terminal edge of the moving article. The foldable article is at this stage folded in half along a transverse axis disposed at the article longitudinal midpoint.

The foldable article is then conveyed over two pinch rollers positioned along the central longitudinal axis of the conveyor and beneath an opening between two spaced tapes which straddle such axis. The tapes slidably move over two smooth-surfaced, spaced plates. An elongate tube having a plurality of downwardly disposed openings is superposed directly over the bite of the two underlying pinch rollers which are rotating in opposite directions. The rotation of the rollers is such that engagement of a foldable article therewith will result in the pulling of the foldable article from the supporting tapes and plates.

Disposed at the ends of the pinch rollers adjacent the folder end is a switch actuator. Upon engagement therewith by the leading bight edge of the once-folded small piece article, compressed air is discharged through the openings of the overlying elongate tube, forcing the transversely folded piece into the bite of the pinch rollers. The foldable article is then folded longitudinally in the course of passing through the pinch rollers, and being discharged between slanted guide tapes leading to an underlying stacking device.

The stacking device comprises two reciprocating series of finger members connected to support bars. The fingers reciprocally move in the horizontal plane into adjacent and spaced relationships. The fingers define a supporting platform in the closed position for the folded pieces slida=bly discharged thereon from the guide tapes. At the end limit of its slidab-le movement onto the finger platform, the article strikes a switch actuator which closes a circuit energizing solenoid valves admitting air into opposed piston and cylinder unit. The units move the platform fingers apart allowing the folded piece to fall onto an underlying continuous conveyor. As one platform portion moves outwardly, another switch actuator is contacted breaking the solenoid-energizing circuit, thereby forcing the solenoids to allow compressed air to return the fingers to their initial platform-forming position.

A reciprocally movable tamping bar may be employed as a part of modified stacking apparatus to assure desired alignment of the quarter-folded items in the vertical plane. The bar is adapted to fixedly position each folded article in precisely the same position on the platform fingers prior to being dropped therefrom onto an underlying conveyor.

The continuous conveyor onto which the folded pieces are discharged may have a drive motor which is periodically and automatically energized after a predetermined number of items have been folded. Thus, stacks of folded items are conveyed to the apparatus operator who not only feeds unfolded items onto the apparatus, but also may receive the folded items from the stack conveyor for further disposal onto carts, tables, or the like, as will hereinafter be explained in greater detail.

For a more complete understanding of this invention, reference will now be made to the drawings wherein:

FIGURE 1 is a fragmentary, schematic, perspective view, partially broken away, illustrating portions of a small piece folder whereby the folding operations are effected;

FIG. 2 is an enlarged end elevational view of apparatus components employed for effecting a first transverse fold on a foldable article;

FIG. 3 is a view similar to FIG. 2 illustrating apparatus components as a fold is being effected on a foldable article;

FIG. 4 is a fragmentary side elevational view of one embodiment of a small piece folder made in accordance with this invention;

FIG. 5 is an end elevational view of the means for driving the pinch rollers of the provided small piece folder;

FIG. 6 is a plan view of a small piece item depicting the axes along which folds will be made;

FIG. 7 is a fragmentary perspective view of the provided apparatus which provide the second fold in small piece items and stack the folded items on an underlying conveyor;

FIG. 8 is a sectional view, partly in elevation, of the pinch rollers and stacking fingers of the provided apparatus;

FIG. 9 is a fragmentary sectional view similar to FIG. 8 illustrating modified stacking components, including a tamping bar, which assure stacking of the folded articles in desired vertical alignment.

FIG. 10 is a fragmentary elevational view illustrating the tamping bar and associated elements which may be employed with the provided folder; and

FIG. 11 is a wiring diagram of the electrical components employed in a stacking arrangement employing a tamping bar.

Referring now more particularly to FIG. 1, there are illustrated the main folding elements of a small piece folder disposed adjacent a conveyor comprising a series of continuous belts or tapes 10 rotatably engaging spaced rollers 12 and 14. The roller 12 also engages a series of longer continuous tapes or belts 16 which engage roller 18 at opposed end portions. Tapes 10 and 16 are adapted to convey a small foldable article, such as a towel, pillow case, napkin, or the like, into two folding stations of a small piece folder 20 (illustrated in side elevation in FIG. 4) of which the elements of FIG. 1 comprise a part.

Interposed between the roller members 12 and 18 is a roller member 22 which supportingly engages the bottom portions of the tapes 16 in the course of their movement. It will be seen from FIG. 4 that adjustable bearings 24 secured to opposed side walls 26 enable the roller 12 to be positioned in desired transverse relationship with the side Walls. Similarly, bearings 28 adjustably journal 0-pposed ends of rollers 14. Also, adjustable bearings 30 engage the opposed ends of rollers 22, and adjustable bearings 32 engage the opposed ends of rollers 18.

It will be seen from FIG. 1 that roller 14 comprises the main drive roller for the folder conveyor belts being driven by motor .13. The output shaft of the motor is coupled to the input shaft of a speed reducer 17. Sprocket 19, mounted on the output shaft of speed reducer 17, engages chain 21 which rotatably drives sprocket 23 secured to an end portion of roller 14.

The side walls 26 are supported by vertical supports 34 and are maintained in desired spaced relationship by means of intenposed brace members 36, the ends of which are illustrated in FIG. 4. Roller 12 is disposed adjacent the feed end of the folder 20. The feed end may on occasion be disposed adjacent the discharge end of an ironer in a laundry. The apparatus 20, however, obviously may be used in a variety of locations, particularly in view of its relatively small size and compact arrangement of parts.

In the normal course of apparatus use, the operator places .a lead edge of the towel, or other small piece item to be folded, on the tapes 10 and 16 moving about the roller 12. Although normally a width-defining edge of the foldable article will be initially placed on the tapes, if the article length is less than the width of the conveying surface defined by tapes 10, a length-defining edge of the article may be initially positioned on the tapes. Care should be taken that the midpoint of the leading edge, whether defining width or length, of the item to be folded coincides with the central longitudinal axis of the folder 20. This may be most easily accomplished by means of a guide plate, such as plate '38, disposed adjacent the roller 12 having a plurality of markings 40 thereon which enable the operator to place items of known width and length over the spaced markings so that the same will be exactly centered in the course of moving onto the tapes 10 and 16. In the event that a small piece item of irregular width is to be inserted onto the small piece folder, the operator may place the center of the same over a center marking 4011 which will assure a fold along a central axis of the small piece item in the course of being processed by the folder 20.

While moving over the tapes- 10 and 16 between the rollers 12 and 14, the leading edge of the small piece item to be folded will come into engagement with a plurality of inclined retractable fingers 42 (illustrated in FIGS. 1 through 3). As is more clearly seen from FIGS. 2 and 3, it is the function of the fingers 42, which are pivotally mounted by means of transverse bar 44 to which afiixed, to enable the leading edge of a small piece article, such as pillow case 46 illustrated in FIG. 2, to ride up the fingers onto the smooth surface of an inclined plate 48. Prior to engaging the inclined fingers 42, the leading edge of the foldable article 46 will move actuator 50 of switch 52 from its normal vertical position, illustrated in dotted lines in FIG. 2, into the inclined solid line position.

After the leading edge of the article 46 has proceeded up the inclined fingers 42 and lower surface portion of plate 48, the edge will engage and move actuator arm 54 of switch 56 in the manner illustrated in FIG. 2, Actuator 54 traverses plate 48 by means of the slot opening 55. Normally-open switches 52 and 56 are in an electrical circuit in series relationship. Thus, upon the foldable article engaging both switch actuators, both switches are closed and an electrical circuit is closed, energizing coils in conventional four-way solenoid valves 58 and 58a, illustrated in FIG. 4. Valve 58 is in communication with a source of compressed air by means of line 60 and regulates the admission of such air into air cylinder 62. A connecting line 61 enables air from line 60 to pass into solenoid valve 58a after first entering T 63, which allows pressure from line 60 to be equally distributed to valves 58 and 58a at all times.

Energization of the coil in valve 58 moves a springbiased valve allowing compressed air to flow into the bottom portion of cylinder 62 by means of line 66a. Energization of the coil in valve 58a moves a spring-biased valve permitting compressed air to flow into the bottom portion of cylinder 64 by means of line 68a. The compressed air flow into the bottoms of cylinders 62 and 64 forces pistons therein (not illustrated) to move upwardly.

Upward movement of the piston of cylinder 62 simultaneously moves attached rod 70, attached clevis 72, and pivotal link 74 connected to clevis 72 by means of pin 76. Link 74 pivotally engages a pin mounted on an arm 75 secured to an end of pivotal bar 78 (see FIGS. 2 and 3), forcing bar 78 to rotate in a clockwise direction (FIGS. 2 and 3) as the pistons move upward. Rotation of bar 78 concomitantly moves clamp bar 80 which is connected to bar 78 by interconnecting bars 82, more clearly seen in FIG. 1.

The clam-p bar 80 is moved downwardly, thereby clamping a leading edge portion of the article 46 against the plate 48 which is fixedly supported on bar 81. Bar 81 is secured at opposed end portions on side walls 26. Plate 48 thus comprises an anvil-like member against which clamp bar 80 may strike in the course of retaining the leading edge of a foldable article in place as a contiguous portion of the flexible foldable article is passing therebeneath.

Also connected in series and simultaneously energized with solenoid valves 58 and 58a is the coil of solenoid valve 84, see FIG. 4, which has a spring-biased valve normally urged into the closed position. Energization of the solenoid coil enables compressed air entering valve 84 from line 86 to pass into line 88 which engages one end of air tube 90, more clearly seen in FIGS. 2 and 3. Discharge openings 90a are directed at the fold of the foldable article 46 so that wrinkling of the article is obviated by discharged air as a fold, such as that illustrated in FIG. 3, is taking place. Needle valve 92 may be employed to regulate the air pressure discharged through openings 90a.

As above noted, solenoid 58a (see FIG. 4) regulates the admission of air into cylinder 64. Engagement of the leading edge of article 46 with switch actuator 54 enables solenoid 58a to admit compressed air into the bottom oi cylinder 64 by means of line 68a. The piston (not illustrated) in cylinder 64, attached rod 98, and clevis 100 are then forced to move upwardly, concomitantly moving link 102 connected to clevis 100 by pin 103 to move upwardly. Upward movement of link 102 connected to one end of bar 44 to which fingers 42 are attached, by means of arm 95, forces the bar and fingers to downwardly pivot (see FIG. 3) to the position illustrated. In the latter position, the fingers are beneath the level of the tapes and 16, which are then able to move the remainder of the article 46 beneath plate 48 without interference from the fingers 42.

To complete a half-fold of article 46 along a transverse axis passing through the longitudinal midpoint of the article, clamp bar 80 must be retracted from engagement with forward edge portion 46l of article 46. The disengagement of the bar 80 must be such that when the forward edge of article 46 is released, it will neatly drop upon terminal edge 462 of the article. Bar 80 is pivoted upwardly into the position of FIG. 2 when the terminal edge 46t passes actuator 50 of switch 52. Inasmuch as switches 52 and 56 are normally in the open position, return of actuator 50 to the normal vertical position will break the electrical circuit energizing the coils and valves in solenoid valves 58, 58a and 84.

Upon breaking the circuit, the spring returns of the valves (not shown) in solenoid valves 58 and 58:! will return the valves to a position which allows compressed air to enter the top of the cylinder 62 by means of line 66 and to enter the top of cylinder 64 by means of line 68. The pistons within the cylinders and the attached piston rods are forced to move in a downward direction. In the course of piston reversal, air within the cylinders 62 and 64 is returned to the solenoid valves 58 and 58a from the cylinders, from which it is released through escape ports. An air flow control device, such as a needle valve, may control the escape of air from the port of valve 58a from which air forced from cylinder 64 escapes. By controlling the rate of escape of the air from cylinder 64, th fingers 42 may be controlled to slowly return to their initial inclined position of FIG. 2 and thereby avoid engagement with, and wrinkling of, an end portion of the folded article 46. Initial upward movement of bar 80, however, instantaneously releases the forward article portion.

Simultaneously with de-energization of the solenoids of valves 58 and 58a, the coil in solenoid valve 84 is deenergized, thereby allowing the spring-biased valve therein to return to the closed position, cutting off the flow of air to the tube 90.

Inasmuch as the relative disposition of the leading and terminal edges of the folded article in the course of effecting the first fold is a function of the inter-actuator distance and the speed of the conveying belts 10 and 16, the interval between the switch actuators should be readily adjustable, as -by means of a turnbuckle or the like. The latter adjustability will enable the actuators to be readily repositioned with change of conveyor speed so that a neat half-fold is assured at all times.

Following the formation of the transverse fold of foldable article 46, it is conveyed into the second portion of the small piece folder solely by belts 16, as illustrated in FIG. 1. Belts 16 slidably move over underlying smoothsurfaced plates 104. The latter plates are spaced apart so as to define an interval over the bite of a pair of underlying pinch rollers 106 and 108, which move in opposite directions of rotation. The rollers 106 and 168 are journaled in bearings disposed in spaced supporting angle irons 110, one of which is more clearly seen in FIG. 7. The latter angle irons may be welded or otherwise suitably secured to opposed side walls 26 of the folder 20 or otherwise suitably positioned in place.

Disposed above the bite of pinch rollers 106 and 108 is an air tube 114, see FIGS. 1 and 5, having a plurality of discharge openings 116 disposed therein at spaced intervals and aligned precisely over the bite of the underlying pinch rollers. Also fixedly mounted above the bite of the pinch rollers adjacent the exit end of the folder 20 is a switch 118 having an actuator arm 120 depending into an end portion of the interval defined by the spaced plates 104.

In the normal course of apparatus operation, after a towel or other foldable article has been folded in half by means of the apparatus components of the folding station illustrated in FIGS. 2 and 3, the foldable article continues to be moved over the plates 104 by means of belt members 16 until the bight edge of the half-folded foldable article engages actuator arm 120 of switch 118. Immediately upon engaging such actuator arm, switch 118 closes a circuit energizing the coil of a solenoid 122 mounted on an end wall of the folder (as illustrated in FIG. 4) to allow compressed air to instantly enter air tube 114 and be discharged through outlets 116 toward the underlying bite of the pinch rollers 106 and 108.

The compressed air forces the longitudinal central portion of the half-folded article into the biteof the pinch rollers in the manner illustrated in FIG. 5. The rollers immediately pull the foldable article from the plates 104 and belts 16 into engagement with continuous guide belts 125 and 126 (see FIGS. 7 and 8). Tapes 126 rotatab y engage pinch roller 106 and an underlying idler roller 128. The foldable article rides down between the pinch rollers on the guide belts and beneath belts 126 onto pposed series of stacking fingers 138 and 140, more clearly seen in FIGS. 7 and 8.

It will be noted more clearly from FIG. 8 that the continuous belts 126 engage and slightly displace the belts 125 from their normal plane by virtue of the positioning of pinch roller 106 and idler roller 128 relative to the positioning of pinch roller 108 and its cooperating idler roller 142. Secure engagement is thereby insured with the folded article. The idler rollers 128 and 142 may be journaled at opposed end limits in bearings disposed in vertical supports, such as bar 146 more clearly seen in FIG. 7.

To assist in maintaining the guide tapes 126 in proper alignment relative to pinch roller 106 and idler roller 128, a plurality of guide fingers 148, illustrated in FIGS. 7 and 8, may be employed. Two fingers straddle each tape 126 so as to maintain the same in desired arrangement on the rotatable rollers driving the same. The guide fingers 148 are secured to a support member, such as bar 150, which may in turn be secured to the undersurface of one of the spaced plates 104 in the manner illustrated in FIG. 8.

FIG. illustrates the drive mechanism whereby the pinch rollers 106 and 108 are driven in opposite directions of rotation by motor 13, which also drives the conveyor belts and 16, as is more clearly seen in FIG. 1. It will be noted from FIG. 5 that motor 13, in addition to having an output shaft which drives drive roller 14 of the conveyor system, has an output shaft having mounted thereon a sprocket 154 which rotatably drives chain 156. The latter chain, in turn, drives sprockets 158 and 160. The latter sprocket drives chain 162, which rotatably drives sprockets 164 and 166 of pinch rollers 106 and 108, respectively, in opposite directions of rotation.

Chain 162 is enabled to drive pinch rollers 106 and i 108 in oposite directions of rotation with the assistance of idler sprocket 168, which also engages the chain 162 in the manner illustrated. It is thus seen from FIGS. 1 and 5 that the single motor 13 has two output shafts whereby the motor is enabled to simultaneously drive pinch'rollers 106 and 108, as Well as the conveyor belts 10 and 16 of the illustrated folding apparatus 20.

It will be more clearly seen from FIG. 7 that the stacking fingers 138 and 140 define a stacking platform in the position illustrated in FIG. 7. Fingers 138 are mounted in support bar 170. The latter bar has secured to opposed end limits thereof collars 172 which are adapted to slidably engage fixedly positioned guide rods 174 which may be mounted in a side wall 26, as illustrated in FIG. 8.

Fingers 140 are mounted in a support bar 176 which has secured to opposed end limits thereof collars 178 which slidably engage guide rods 180, which are mounted in one of the walls 26 of the folding device, as illustrated in FIG. 8. The guide rods 180 and connected elements illustrated in FIG. 8 exteriorly of one wall 26 would normally be covered by a housing, not illustrated, to obviate injury to nearby personnel and dirt contamination.

In the normal folding operation, an article is folded transversely by means of the appartaus components illustrated in FIGS. 2 and 3, and folded longitudinally by means of the pinch rollers 106 and 108. The quarterfolded piece is then driven between the guide belts 125 and 126, more clearly seen in FIG. 8, and slidably moved over the stacking fingers 138 and 140 until the leading edge of the folded article strikes switch actuator 182. The specific arrangement of the belts 125 and 126 may depart from the position illustrated to make maximum use of available space beneath the pinch rollers.

Actuator 182 closes switch 184, which closes a circuit energizing the coil in a solenoid valve 186, illustrated in FIGS. 4 and 8. The coil in valve 186 regulates the disposition of a spring-loaded valve member governing the flow of air which enters valve 186 by means of line 188, which is in communication with a source of compressed air. When the circuit is closed so that the coil of valve 186 is energized, air passes to the left-hand portion of cylinder 190, illustrated in FIG. 8 by means of line 192.

Simultaneously with the latter coil actuation, the coil of solenoid valve 186a in series relation with the coil of solenoid 186 is energized so as to pass compressed air into the right-hand portion of cylinder 194 of FIG. 8 through line 195, the air entering the valve 186a by means of line 196. Thus, as the circuit is closed, the solenoid valves are actuated so that air enters the cylinders 190 and 194, so as to drive the fingers 138 and rapidly into spaced relationship. The quarter-folded small piece item which had been deposited on the stacking platform defined by the fingers 138 and 140 then vertically falls as the fingers retract into spaced relationship onto an underlying continuous conveyor 198, more clearly seen in FIGS. 4 and 7.

The stacking fingers 138 and 140 are retracted into spaced relationship by virtue of the connection of piston rod 200 with support bar 176 through means of a clevis 202. The clevis is attached to piston rod 200 of cylinder 190 and also pivotally engages spaced plates 204 which may be welded or otherwise suitably secured to the support bar 176 in the manner more clearly illustrated in FIG. 7.

It will be noted from FIG. 8 that piston rod 206 of cylinder 194 is similarly connected to support rod of the stacking fingers 138 by means of clevis 208 and connecting plates 209.

After the stacking fingers 138 and 140 have been driven by their respective cylinders 194 and into spaced relationship whereby the fingers 138 move to the left and the fingers 140 move to the right, as viewed in FIG. 8, it will be noted that bar 170 for fingers 138 will strike a switch actuator 210 of switch 211, which will break the circuit energizing the coils of solenoid valves 1'86 and 186a. As a result, the spring-loaded valve members in each of these two valves will instantly move into a position which allows compressed air to flow into the left-hand portion of cylinder 194 through line 212, and into the right-hand portion of cylinder 190 through line 214, so as to return the fingers 138 and 140 into the platform-defining position illustrated in FIGS. 7 and 8.

Because of the instantaneous reciprocal movement of the fingers 138 and 140, and because of the small surface contact between the fingers and the quarter-folded articles deposited thereon by the belts 126 and 125, the folded articles will drop in a substantially vertical position onto the underlying conveyor 198. Thus, neatly formed stacks, such as stacks 46s, illustrated in FIG. 4, may be formed on the conveyor 198.

The conveyor 198 is seen in 'FIG. 7 to comprise continuous belts or tapes 216 which rotatably engage opposed rollers 218 and 218a (see FIG. 4). One of the rollers, such as roller 218, may be driven by means of a motor 220 through a gear box 222, sprocket 224, and chain 226, which engages a sprocket 228 secured to the one end of roller 218 in the manner illustrated in FIG. 7.

The conveyor may be automatically operable so as to move a predetermined distance by means of an electric impulse counter 230, seen in FIG. 7. Counter 230 may be set to close the circuit energizing motor 220 after a predetermined number of electrical impulses have been im parted thereto. Impulses may be imparted to the counter 230 by one of the solenoid valves operable in the apparatus 20, such as solenoid valve 122, which regulates the admission of :air into air tube 114; solenoid 122 is more clearly seen in FIGS. 1 and 4.

After a predetermined number of impulses have been imparted to counter 230 by means of the solenoid valve 122 through conduit 123, relay 231 is closed, closing a circuit which energizes the motor 220, thereby rotating the driving sprocket 224. Sprocket 224 may have a circuitbreaking means, such as pin 232, secured to a peripheral portion thereof which breaks the circuit by cont-acting actuator arm 234 of limit switch 236. However, before the pin 230 has engaged the switch actuator 234, the conveyor belts 216 will have been moved a desired distance so as to provide an open conveyor space beneath the stacking platform defined by fingers 138 and 140. The conveyor 198 may also be directly controlled by a switch accessible to the apparatus operator who also feeds the items onto the conveyor tapes.

It will be seen from FIG. 4 that the conveyor belts 216 have disposed thereon stacks of quarter-folded items, each stack comprising five items. Accordingly, the impulse counter 230 has been set for five impulses and it will be further noted from FIG. 4 that the conveyor is so connected to the driving means so that the stacked items are being conveyed to the right in FIG. 4, or to the feed end of the apparatus. Accordingly, the operator feeding the foldable items onto the tapes of apparatus 20 may also take the stacked folded items from the conveyor 198 intermittently with the feeding operations. Obviously, the conveyor 198 may also be driven so as to move toward the discharge end of the apparatus 20, whereat an assistant may receive the stacked items for further disposal.

The duration of many of the previously-described operations is extremely short. It will be noted that in the formation of the second longitudinal fold by means of the pinch rollers 106 and 108, the fold is effected substantially instantaneously. The folded item 46 is instantly pulled from the moving tapes 16 and the smooth plates 104 over which the half-folded item is moved. The item 46 is carried by the tapes 16 with only a relatively small area of contact between the item and the spaced tapes. Avoidance of wrinkling is assured during the formation of the second fold by rendering the same substantially instantaneously, that is, by regulating the surface speed of the pinch rollers'106 and 108 so that the same is greater than that of the tapes 16 moving over the plates 104.

By way of example, tapes 16 may possess a speed of 115 feet per minute and the pinch rollers may have a surface speed of 1 65 feet per minute. The latter speed will result in a smooth wrinkle-free quarter-folded item being discharged onto the platform formed by fingers 138 and 140. To assist in the formation of a desired vertical stack on the conveyor 198, a stop plate 238 may be secured to a wall member 26, as illustrated in FIG. 8, adjacent switch actuator 182 so as to insure the precise locationing of a quarter-folded item prior to being dropped onto the underlying conveyor 198 in the course of reciprocal movement of the fingers 138 and 140. Although fingers 138 are longer than fingers 140 because of the necessity of traversing the intervals between tapes 125, it is desirable that substantially equal surface portions of the folded articles be deposited on the platform portions. Equal surface area distribution will assure equal frictional 'drag exerted on the article by the fingers of the two platform portions and assist in assuring dropping of the folded article in the vertical plane. The stop plate 238 in addition to limiting the movement of foldable articles over the fingers 140, also serves to strip the foldable articles from the fingers 140, thereby insuring stacking of the dropped foldable articles in a desired vertical alignment. Movement of the platform portions at exactly the same speeds also tends to neutralize the effect of frictional drag exerted by the fingers.

The air discharging through outlets 116 of air tube 114 need only be instantaneous, that is, need only be discharged until the pinch rollers have engaged the center of the overlying foldable article. The air pressure discharging into the interval between the plates 104 in the manner illustrated in FIG. may be at 100 pounds per square inch, which has been found to perform satisfac- 1G torily for folding small piece articles, such as towels, pillow cases, and the like. The air pressure dis-charging through outlets a of air tube 90, more clearly seen in FIGS. 2 and 3, need not be so great and may be in the neighborhood of 80 pounds per square inch, the latter pressures being given 'by way of example only.

On occasion, particularly when stiff fabrics of a certain minimum weight are being folded and stacked, the quarter-folded item may strike stop plate 238 and rebound. Such rebounding of the individual items from the stop surface results in an uneven underlying vertical stack because of the variance in positioning of the folded items on the fingers 138 and 140 after such items have come to rest.

A tamping bar may be employed to eliminate any rebounding from the stop plate 238 or other stop surface. Such a bar 250 is illustrated in FIG. 9, wherein a slightly different arrangement of guide belts depending from the pinch rolls is illustrated. Continuous belt 252, which moves about roller member 108, as well as idler rollers 254, 256, 258 and 260 cooperates with continuous belt 262 which rotatably is'driven by pinch roller 106. Belts 252 and 262 are intended to function similarly to abovedescribed belts and 126. However, by driving the folded articles first to the left and then to the right, as illustrated in FIG. 9, space is made available beneath the smooth-surfaced plates 104 for the tamping bar 250 and other apparatus components.

In FIG. 10, tampingbar 250 is seen to comprise an elongate rigid strip 264 having a soft pad 266 of foam rubber or the like secured to the undersurface thereof. Opposed end portions of the strip are fixedly secured to distal ends of piston rods 268 which reciprocally move in cylinders 270. Movement of the cylinder pistons (not shown) 'within the cylinders is governed by solenoid valve 272 having a spring-biased valve therein which in the normal position allows air to pass through conduits 274 whereby the tamping bar is maintained in an elevated position.

Upon energization of the coil of valve 272, a springbiased valve is moved to permit air to exit the valve into conduits 276 whereby the pistons of valves 270 urge the tamping bar 264 into the lowered position. It will be noted from FIG. 10 that a striker member 278 is secured to the upper central portion of the strip 264 so as to engage actuating button 280 of switch 282 when in the upper position and actuating button 284 of switch 286 when in the lowered positions.

Normal operation of the tamping bar mechanism may be followed by referring to the wiring diagram comprising FIG. 11. Upon a quarter-folded article striking actuator 182a of normally open switch 184a, the switch is closed and normally-open contacts 289 of relay 290 are closed. Relay contacts 291 are simultaneously closed, energizing the coil in solenoidvalve 272 thereby reversing the air flow into the cylinders 270. The tamper bar 250 is substantially instantaneously lowered engaging a quarter-folded article before the same strikes and rebounds from surface 26 (see FIG. 9). Proper disposition of the switch actuator 182a relative to the tamper bar will assure engagement with the quarter-fiolded article at the desired position during its travel over the fingers 138 and 140.

At the end of its downward movement, striker 278 of tamper bar 250 engages actuator 284 of normally-open switch 286, thereby energizing relay 292. Energization of the latter relay closes relay contacts 294. Simultaneously relay contacts 296 are opened, de-energizing the coil of solenoid valve 272, thereby allowing air to enter cylinders 270 through inlets 274 and raise the tamper bar 250.

At the end of its upward movement, striker 278 depresses actuator 280 of switch 282 closing the same, thereby energizing the coil of solenoid valves 18612 and 1860 (see FIG. 9) which allow air to enter cylinders 1 ll 194a and 190a through conduits 195a and 192a, so as to separate fingers 138 and 140. The cylinders have rods 206a and 200a, respectively, reciprocally movable therein. The rods drive connectors 209a and 204a, respectively, which are joined to the reciprocally movable fingers 138 and 140.

The quarter-folded article disposed on the fingers then drops onto the underlying conveyor 198, and the successively deposited articles form a neat vertical stack because of their precise and uniform positioning relative to wall 26. As fingers 138 move outwardly, actuator arm 301 of double pole switch 302 is contacted by connector 209a and normally-closed contacts 300 of the switch 302 are opened and both relays 200 and 292 are de-energized. The fingers are returned to their platform-defining position. Simultaneously contacts 304 of switch 302 are closed giving an impulse to counter 230a. After the folded article drops, switch 184a opens and the stacking and tamping portion of the apparatus is ready to repeat the foregoing cycle.

It is seen from the foregoing description, therefore, that a small piece folder has been provided which is inexpensive to construct, inexpensive to operate, and yet forms precise folds along intersecting transverse and longitudinal axes of a small piece foldable article. The twicefol ded foldable article is thus quarter-folded when discharged from the apparatus for stacking purposes.

Each small piece foldable article processed by the above-described apparatus may be precisely folded along a transverse axis, such as axis A of FIG. 6 disposed midway of the article length. The once-folded article is then folded along central longitudinal axis B, as illustrated in FIG. 6, to provide an ultimately quarter-folded item. However, the small piece folder 20 of this invention does not rely on any mechanism which effects a measuring function.

The folds are effected solely by contact of leading edge portions of the foldable item as it moves along conveying tapes or belts. The foldable article itself by contacting switch actuators effects energization of the folding elements in a rapid and efiicient manner. Operators employing the small piece folder of this invention need only initially center the item to be folded as it is placed on the conveying tapes 10 and 16 of the apparatus. Following this initial centering operation, which may be assisted by the use of means such as plate 38 previously described, the operator need do nothing in the Way of apparatus regulation.

Known folders of the type described employ either complex measuring devices which are expensive and subject to malfunction or, in the alternative, must rely upon operator manipulation in the course of processing of the foldable article. The apparatus of this invention comprises a notable advance in the art, being the first apparatus of its kind to quarter-fold utilizing simple elements of the type above described.

Obvious modifications may be made in the disclosed apparatus which do not withdraw the resulting assemblies from the spirit of the invention disclosed. It is apparent, for instance, that the fingers of the stacking platform may be substituted by plate members which function to equal advantage. Rearrangement of conveyor belts so as not to traverse the plane of the plates will allow the same to function similarly to the described fingers 138 and 140.

Without further elaboration, the foregoing will so fully explain the character of our invention that others may, by applying current knowledge, readily adapt the same for use under varying conditions of service, while retaining certain features which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to us by the following claims.

We claim:

1. In a compact folding apparatus, the combination comprising spaced continuous conveyor means for conveying articles to be folded, means associated with said conveyor means for effecting a transverse fold in a foldable article while conveyed by said spaced conveyor means, the associated means for effecting a transverse fold being actuated by engagement with said foldable article while conveyed by said conveyor means; mating rotatable means, disposed beyond and adjacent said means for effecting a transverse fold and having the bite thereof disposed beneath a portion of a longitudinal opening between said spaced conveyor means, said rotatable means being adapted to engage a folded foldable article and substantially instantaneously pull the same through said longitudinal opening while moving on said spaced conveyor means; and means associated with said conveyor means and said rotatable means being actuated by engagement with a fold able article carried by said conveyor means for urging substantially a central axial portion of a once-folded fold able article moving on said conveyor means into the bite of said rotatable means whereby the once-folded foldable article may be folded a second time in the course of passing through said spaced conveyor means.

2. In a stacking device, a supporting platform for folded articles or the like, said platform comprising discrete portions adapted to rapidly move in substantially the horizontal plane into spaced and adjacent relationships whereby articles disposed on said platform drop in substantially a vertical plane from said platform when the portions thereof are rapidly moved into spaced relationship; means for moving said platform discrete portions into spaced and adjacent relationships, and means for actuating the moving means to move the platform portions into spaced relationship sensitive to the movement of articles onto said platform.

3. In a folding apparatus, the combination comprising first means for folding a moving foldable article in half along an axis normal to the article axis of movement; second means for folding a foldable article, folded in half along an axis normally disposed to the article axis of movement, along an axis disposed at right angles to the first folding axis whereby said fold-able article is folded into quarters; means for conveying said fold-able article into contact with the first and second folding means; a supporting platform for foldable articles, means for conveying a quarter-folded, foldable article from said second folding means onto said supporting platform, said platform comprising opposed, reciprocally movable portions adapted to rapidly part in substantially the horizontal plane whereby a quarter-folded article disposed thereon may vertically drop therefrom; means for reciprocally moving the opposed portions of said platform, actuator means for the platform moving means disposed in the path of -a foldable item conveyed onto said platform, and means disposed beneath said platform for receiving articles dropped from the overlying platform and conveying the same from the vicinity of said platform.

4. The combination of claim 3 in combination with means sensitive to the number of foldable articles dropped from said platform onto said means disposed beneath said platform for automatically moving said latter means a predetermined interval after a predetermined number of foldable articles have dropped from said platform.

5. The combination of claim 3 in which each of said platform portions is composed of spaced supporting elements engaging a minor portion of the bottom surface area of the folded articles deposited thereon.

6. In a folding apparatus the combination comprising means for folding a foldable article, a supporting platform for folded articles, means for conveying folded articles from the folding means onto said supporting platform, said platform comprising discrete portions adapted to rapidly move in substantially the horizontal plane into spaced and adjacent relationships, folded articles disposed on said platform dropping in substantially a vertical plane from said platform when the portions thereof are rapidly moved into spaced relationship; means for moving said platform discrete portions into spaced and adjacent relationships, and means for actuating the moving means to move the platform portions into spaced relationship disposed in the path of the foldable articles in the course of being moved onto said platform.

7. The apparatus of claim 6 in combination with means for actuating the moving means to move the platform portions into adjacent relationship positioned so as to be engageable with one of the platform portions when the same are in spaced relationship.

8. The apparatus of claim 6 in which the means for moving said platform portions into spaced relationship moves both of said platform portions at exactly the same speed.

9. The apparatus of claim 6 in combination with predeterminately positioned stop means for stopping the movement of folded foldable articles onto said supporting platform at desired positions relative to the inner ends of said reciprocally movable platform portions.

10. In a folding apparatus, the combination comprising means for folding a foldable article, a supporting platform for folded articles, means for conveying folded articles from the folding means onto said supporting platform, said platform comprising opposed portions having distal portions reciprocally movable in substantially the horizontal plane into spaced and adjacent relationships, means for stopping the conveyed folded articles moved onto said supporting platform so that substantially equal surface portions of each of said articles are supported on each of the opposed platform portions, and means for rapidly moving said platform portions into spaced and adjacent relationships.

11. In a folding apparatus, the combination comprising means for folding a foldable article, a supporting platform for folded articles, means for conveying folded articles from the folding means onto said supporting platform; said platform having opposed portions, separable along a substantially linear axis of separation, reciprocally movable in substantially the horizontal plane into spaced and adjacent relationships; said platform portions comprising uniformly spaced parallel fingers; the combined intervals between said fingers being greater than the combined thicknesses of said fingers, and means for rapidly moving said platform portions into spaced and adjacent relationships.

12. In a folding apparatus, the combination comprising means for folding a foldable article, a supporting platform for folded articles, means for conveying folded articles from the folding means onto said supporting platform, said platform having opposed portions defined by spaced fingers reciprocally movable in substantially the horizontal plane into spaced and adjacent relationships; means for stopping said folded articles in the course of moving onto said platform whereby substantially equal portions of said folded articles are supported on said opposed portions, and means for rapidly moving said platform portions at eqnal speed into spaced relationship whereby a folded article supported thereby may drop therefrom in a substantiarlly vertical plane.

13. In a folding apparatus in which foldable articles are folded and slidably discharged onto a supporting platform, the improvement comprising means disposed adjacent said platform and movable upon contact with a folded article discharged onto sn h supporting platform while on said platform, means operable in accordance with the position of the movable means adapted to engage and terminate slidable movement of said folded article thereover at a predetermined locus on said platform, and means for withdrawing the article-engaging means from engage ment with said folded article after said article has stopped.

14. In a folding apparatus in which foldable articles are folded and moved onto a supporting platform, the improvement cornprising means disposed adjacent said platform for reciprocally moving toward engagement with said platform and into a spaced position relative to said platform; means sensitive to the presence of a folded article when in a predetermined position on said platform for actuating the reciprocally moving means toward said platform, said reciprocally movable means being so positioned relative to the article-sensitive means as to engage said folded article when said reciprocally movable means is actuated toward said platform; and means for moving said reciprocally movable means into the spaced position after engagement with said folded article.

15. In a folding apparatus, the combination comprising means for folding a foldable article, a supporting platform for folded articles having opposed portions movable into a spaced relationship and an adjacent relationship defining a supporting surface, means for discharging folded articles onto said platform when 'said opposed portions thereof define a supporting surface, means sensitive to the presence of folded articles while being discharged onto said platform disposed in the path of such folded articles in the course of discharge, means movable against said platform from a spaced position for stopping the folded articles at a desired location on said platform and actuated after the article-sensitive means has engaged a folded article, means for moving the article-stopping means into said spaced relationship after said article-stopping means has effected engagement with said folded article, and means for moving the platform opposed portions into spaced relationship after said article-stopping means has withdrawn from engagement with said folded article.

16. In a folding apparatus, the combination comprising first means for folding a moving foldable article in half along an axis normal to the article axis of movement; second means for folding a foldable article, folded in half along an axis normally disposed to the article axis of movement, along an axis disposed at right angles to the first folding axis whereby said foldable article is folded into quarters; means for conveying said foldable article into contact with the first and second folding means; a supporting platform for foldable articles, means for conveying a quarter-folded, foldable article from said second folding means onto said supporting platform, said platform comprising opposed, reciprocally movable portions adapted to rapidly part in substantially the horizontal plane whereby a quarter-folded article disposed thereon may vertically drop therefrom; means for reciprocally moving the opposed portions of said platform, actuator means for the platform moving means disposed in the path of a foldable item conveyed onto said platform, means reciprocally movable toward said platform adapted to engage a foldable item in the course of moving over said supporting platform whereby items conveyed onto said platform may stop at a uniform point thereon, and means disposed beneath said platform. for receiving articles dropped from the overlying platform and conveying the same from the vicinity of said platform.

References Cited by the Examiner UNITED STATES PATENTS 1,898,794 2/1933 Spiess 270 -62 2,106,953 2/1938 Ludewig 270-83 3,094,321 6/1963 Kamberg 270-68 EUGENE R. CAPOZIO, Primary Examiner.

NELSON M. ELLISON, Assistant Examiner. 

1. IN A COMPACT FOLDING APPARATUS, THE COMBINATION COMPRISING SPACED CONTINUOUS CONVEYOR MEANS FOR CONVEYING ARTICLES TO BE FOLDED, MEANS ASSOCIATED WITH SAID CONVEYOR MEANS FOR EFFECTING A TRANSVERSE FOLD IN A FOLDABLE ARTICLE WHILE CONVEYED BY SAID SPACED CONVEYOR MEANS, THE ASSOCIATED MEANS FOR EFFECTING A TRANSVERSE FOLD BEING ACTUATED BY ENGAGEMENT WITH SAID FOILDABLE ARTICLE WHILE CONVEYED BY SAID CONVEYOR MEANS; MATING ROTATABLE MEANS, DISPOSED BEYOND AND ADJACENT SAID MEANS FOR EFFECTING A TRANSVERSE FOLD AND HAVING A BITE THEREOF DISPOSED BENEATH A PORTION OF A LONGITUDINAL OPENING BETWEEN SAID SPACED CONVEYOR MEANS, SAID ROTATABLY MEANS BEING ADAPTED TO ENGAGE A FOLDED FOLDABLE ARTICLE AND SUBSTANTIALLY INSTANTANEOUSLY PULL IN SAME THROUGH SAID LONGITUDINAL OPENING WHILE MOVING ON SAID SPACED CONVEYOR MEANS; AND MEANS ASSOCIATED WITH SAID CONVEYOR MEANS AND SAID ROTATABLE MEANS BEING ACTUATED BY ENGAGEMENT WITH A FOLDABLE ARTICLE CARRIED BY SAID CONVEYOR MEANS FOR URGING SUBSTANTIALLY A CENTRAL AXIAL PORTION OF A ONCE-FOLDED FOLDABLE ARTICLE MOVING ON SAID CONVEYOR MEANS INTO THE BITE OF SAID ROTATABLE MEANS WHEREBY THE ONCE-FOLDED FOLDABLE ARTICLE MAY BE FOLDED A SECOND TIME IN THE COURSE OF PASSING THROUGH SAID SPACED CONVEYOR MEANS. 